Cook the egg in boiling water for about 10 minutes. Rinse with cold water and peel off the shell. Leave to cool. Drain cucumbers and dice finely. Peel and finely dice the onion.
Cut cress from the bed, wash chives, shake dry and cut into fine rolls. Finely dice the egg. Mix mayonnaise, crème fraîche, gherkins, herbs, onion and egg. Season to taste with salt and pepper
Wash the salad and dab dry. Wash sprouts and currants and drain well. Spread rye bread with the tartar sauce. Spread the lettuce on top. Cut cheese slices in half or in thirds and lay on top in several layers. Garnish with sprouts and redcurrants